Due to technological advancements, people are migrating to urban areas for
better health care, employment, amenities, and education. Communication technology
innovations are going to play a crucial role in smart cities. These technologies are the
heart and brain of the smart city. In this chapter, various technologies like IoT and
cyber-physical systems (CPS) have been discussed. Security challenges for IoT and
CPS are pointed out in this chapter, and solutions to these challenges are also
Keywords: Cyber-Physical systems, Intrusion Detection System (IDS), IoT, Security, Smart cities.